Torsion bar for scraper elevator frame

ABSTRACT

In a self-loading scraper having an elevator frame, a torsion shaft interconnecting the lower elevator frame support link members so as to provide a stable suspension means for the elevator frame. The torsion shaft is fixed relative to the support links and mounted for movement relative to the elevator frame.

United States Patent Inventor Larry G. Eftefield Juliet, I11.

Appl. No. 813,191

Filed Apr. 3, 1969 Patented July 20, 1971 Assignee Caterpillar Tractor Co. Peoria, [IL

TORSION BAR FOR SC RAPER ELEVATOR FRAME 7 Claims, 5 Drawing Figs.

use: 37/8,

lnLCl 860p 1/38 Field of Search 37/4, 8, 126

[56] References Cited UNITED STATES PATENTS 3,210,868 10/1965 Liess 37/8 3,331,149 7/1967 Rapp 37/8 3,381,396 5/1968 Klein 37/8 OTHER REFERENCES WEBSTER S THIRD NEW INTERNATIONAL DIC- TIONARY (UNABRIDGED), p ge 2201 Spline Shaft Primary Examiner-Robert E. Pulfrey Assistant Examiner-Clifford D. Crowder Att0rneyFryer, Tjensvold, Feix, Phillips & Lempio ABSTRACT: In a self-loading scraper having an elevator frame, a torsion shaft interconnecting the lower elevator frame support link members so as to provide a stable suspension means for the elevator frame. The torsion shaft is fixed relative to the support links and mounted for movement relative to the elevator frame.

'PATENTEU mu m SHEET 1 OF 3 INVENTOR LARRY G. EFTEFIELD PAIENTED JULZO ISYI SHEET 3 OF 3 vhz INVENTUR LARRY G. EFTEFIELD BY P +2 J i M ATTORNEYS One of the more important earthmoving vehicles has proven to be the tractor-drawn scraper. Scrapers usually have a soilcutting blade at the lower forward edge of a load-carrying bowl, and in some instances are provided with a continuous chain conveyor extending upwardly from the blade to form a front boundary of the bowl. This conveyor, commonly known as an elevator, functions to lift soil from the region of the blade and thereby reduce the resistance which the load offers to the movement of additional soil into the bowl. The elevator often eliminates any need for using a separate pusher tractor with the scraper in order to fully load the bowl.

The elevator of the self-loading scraper is subjected to a variety of uneven forces as material is loaded by the elevator into the scraper bowl. These forces tend to twist the elevator frame.

It is therefore an object of this invention to provide a means to resist the loads imposed upon the elevator frame and provide stability within the elevator.

It is also an object of this invention to provide an elevator frame in which a torsion shaft is utilized to resist the loads imposed upon the frame.

It is a further object of this invention to provide such a scraper wherein the torsion shaft interconnects two lower support link members on the frame so as to provide a stable suspension means therefor.

Other objects and advantages of the present invention will become apparent from the following description of the ac companying drawings, which illustrate what is presently considered to be the best mode contemplated for applying the principles of the present invention. Those skilled in the art will readily recognize that other modes or embodiments of the invention utilizing the same or equivalent principles may be utilized.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view, partly in section, of a tractordrawn self-loading scraper, having the elevator mounting structure of the preferred embodiment thereon;

FIG. 2 is a view of the elevator frame taken along a line IIII of FIG. 1;

FIG. 3 is a view, partly in section, of the lower left hand comer of the frame as viewed in FIG. 2;

FIG. 4 is a view, similar to FIG. 3, but sectioned to show the detail of a second embodiment of the elevator frame downstop means; and

'FIG. 5 is a sectional view of the alternate down-stop means taken along a line V-V of FIG. 4.

DETAILED DESCRIPTION Referring now to the drawings, and particularly to FIG. 1 thereof, a scraper 12 has a bowl assembly 13 mounted on a pair of rear wheels 14 by a frame 16. The scraper is drawn by a two-wheel'tractor 17 through a pair of draft arms 18 which extend along opposite sides of the bowl l3 and are coupled thereto by pivots 19. The forward ends'of the draft arms I8 attach to a-transverse spreader 21 which is coupled to the tractor-17 by a gooseneck 22 and a swivel hitch 23.

The bowl assembly 13 may be raised and lowered'by operation ofhydraulic jack 27 connectedbetween the spreader 21 and the forward portion of the scraper frame 16. The lifting and lowering of the bowl 13, through a pivoting movement about the axis of the rear wheels 14, may be for the purpose of adjusting the depth of cut or for raising the bowl to transport a load.

A cutting blade 28 is disposed along the lower forward edge of the bowl 13 and projects forwardly and downwardly therefrom to cutaway a layer of soil and to guide the soil into bowl 15.

In such self-loading scrapers, the movement of soil from blade 28 into bowl 13 is assisted by an elevator generally illustrated at 43 which has a lower end situated above the blade 28 and slightly forward therefrom. The elevator 43 extends up 5 from the blade 28 and is inclined rearwardly, in effect, form- III ing the forward boundary of the bowl 13.

In this embodiment, the elevator 43 is of the type having a frame 44 with a pair of spaced apart sprocket gears 46 journaled at the top thereof and a pair of idlers 47 at the lower end. An endless chain 48 is engaged on each pair of sprockets 46 and idlers 47 on either side of the frame 44, and carry a plurality of transverse flights, one of which is illustrated at 49 in FIG. 2. Idler rolls 5! are mounted on the side rails of frame 44 at spaced intervals to support the intermediate portions of the chain 48. To drive the elevator 43, a hydraulic motor 52 is coupled to the upper sprocket gears 46 by a shaft 53.

The upper end of the elevator may be supported by a pair of links 55 which are pivoted to the frame at joints 57 and to the scraper bowl sidewalls at the pivot points 59. If desired, links 55 could be replaced by hydraulic cylinders which would allow the scraper operator to control the angle of inclination of the elevator relative to the bowl.

The lower end of the elevator is mounted on the vehicle by a pair of lower support arms 61 which are disposed on opposite sides of the elevator frame. The forward ends of the arms are journaled, by a pair of spaced bearings 63 and 65 as shown in FIG. 3, on outwardly projecting shafts 67. The rear ends of the arms 61 are connected by ball and socket joints 68 to the sides of the bowl I3.

Downward movement of the elevator may be limited by arms 61 contacting stop surfaces 69 on the sidewalls of the bowl. When pressure from the dirt or rock forces the elevator frame upwardly, the links 61 are limited in their upward movement by contact with up-stop surfaces 70 on the sidewalls.

The forward ends of the arms 61 are interconnected by a torsion shaft 71 which extends through a lower cross tube 72 of the elevator frame 44. The ends of the shaft 71 are splined, as at 73, and engage a pair of end caps 75 which are fastened to the arms 61, such as by bolts 77.

An alternate apparatus which may be utilized to limit the movement of the lower end of the elevator frame is illustrated in FIGS. 4 and 5. As shown, a spring stop 81 is mounted on the torsion shaft 71 at a machined section 83 thereof. The movement of the elevator is limited by outward projecting lobes 85 and 87 on the shaft which contact stop locks 89 and 91 on the lower elevator cross tube 72. The spring stop means reduces shock loading in the elevator frame by allowing some windup in the torsion bar before the movement of the elevator is stopped.

In operation, the elevator frame of this invention permits the lower ends of the elevator to pivot upward and downward so as to override obstacles and to adjust to varying depths of cut and varying soil textures. The use of a torsion shaft provides lateral stability for the elevator by equalizing the forces which are transmitted laterally on the frame. The torsion shaft will also insure that, should actuating cylinders be utilized to raise the upper end of the elevator, such cylinders will remain in phase since the forces acting through the elevator frame would be applied substantially equally.

When one comer of the elevator is subjected to a twisting force, such as may happen when an elevator flight contacts a rock or some other obstruction, the interconnecting torsion shaft 71 causes the torque forces acting on the elevator to be transferred equally into the support arms 61 due to the twisting of the shaft.

If desired, the torsion shaft could be associated with the upper links, but it is considered to be more desirable to have the shaft as close as possible to the load which acts upon the frame, thus preventing any undue twist or warping of the frame.

In summary, the Applicant has invented an apparatus for stabilizing a self-loading scraper elevator frame, wherein what is claimed as the invention is:

I claim:

1. In an elevator for a self-loading scraper, the elevator having a frame means, first means moveably mounting the upper portion of the frame means to the scraper on each side thereof, and second means moveably mounting the lower portion of the frame means to the scraper on each side thereof, the improvement comprising torque transmission means in said frame means, said torque transmission means being mounted for movement relative to said frame means, said torque transmission means being rigidly fixed to said mounting means on one side of said frame means and to the corresponding mounting means on the other side of said frame means such that torsion produced in one side of said frame means is transmitted by said torque transmission means to said other side of said frame means.

2. The elevator of claim I wherein the torque transmission means comprises a torsion bar means extending from said connection with said mounting means on one side of the frame means to a connection with a corresponding mounting means on the other side of the frame means.

3. The elevator of claim 1 wherein the torque transmission means connects the second mounting means on each side of .for limiting the movement of the frame means relative to the scraper.

5. The elevator of claim 1 including means interacting between the torque transmission means and the frame means for limiting the movement of the frame means relative to the scraper.

6. The elevator of claim 5 wherein the torque transmission means comprises a torsion bar means rotatably extending through the frame means and the interacting means comprises a spring stop means mounted on the torsion bar means and on the frame means.

7. The elevator of claim 6 wherein the torsion bar means is splined to one end of each of the said second moveable mounting means and wherein said torsion bar means is coaxially enclosed by a tubular spacer means which extends axially coterminously with said torsion bar means. 

1. In an elevator for a self-loading scraper, the elevator having a frame means, first means moveably mounting the upper portion of the frame means to the scraper on each side thereof, and second means moveably mounting the lower portion of the frame means to the scraper on each side thereof, the improvement comprising torque transmission means in said frame means, said torque transmission means being mounted for movement relative to said frame means, said torque transmission means being rigidly fixed to said mounting means on one side of said frame means and to the corresponding mounting means on the other side of said frame means such that torsion produced in one side of said frame means is transmitted by said torque transmission means to said other side of said frame means.
 2. The elevator of claim 1 wherein the torque transmission means comprises a torsion bar means extending from said connection with said mounting means on one side of the frame means to a connection with a corresponding mounting means on the other side of the frame means.
 3. The elevator of claim 1 wherein the torque transmission means connects the second mounting means on each side of the frame means.
 4. The elevator of claim 1 including means on the scraper for limiting the movement of the frame means relative to the scraper.
 5. The elevator of claim 1 including means interacting between the torque transmission means and the frame means for limiting the movement of the frame means relative to the scraper.
 6. The elevator of claim 5 wherein the torque transmission means comprises a torsion bar means rotatably extending through the frame means and the interacting means comprises a spring stop means mounted on the torsion bar means and on the frame means.
 7. The elevator of claim 6 wherein the torsion bar means is splined to one end of each of the said second moveable mounting means and wherein said torsion bar means is coaxially enclosed by a tubular spacer means which extends axially coterminously with said torsion bar means. 